An apparatus of the generic type for machining a strip- or plate-shaped metallic workpiece is known from WO 2004/039536 A1.
During the laser cuffing, in particular also during the plasma cuffing, of metallic workpieces, burrs form at the cut edges, and these burrs have to be removed before the further machining of the workpiece, for example before the latter is enameled.
Furthermore, plate-shaped metallic workpieces often have on their surfaces or main surfaces discoloration, residues or the like, which have to be removed before further processing or finishing. This is intended to avoid a situation in which, for example, enameling or galvanizing to be applied comes off again relatively quickly. For this reason, the surfaces of the metallic workpieces are ground before the enameling or galvanizing.
Apparatuses for deburring and precision grinding are known from the general prior art. In this case, both rolls and plate-like, rotating brush tools are used. In the known apparatuses, the workpiece to be machined is placed on a horizontal working plane or a conveyor belt and is passed through under the roll or the rotating brush tool by hand or automatically. It is a disadvantage in this case that the workpieces as a rule are always pushed in at the same location, such that uneven wear of the roll or of the brush tools is affected. Such machines can have, for example, a working width of 1 to 2 m, but in practice are mostly furnished with smaller metal blanks. The result of this is that a roll having a length of, for example, 2 m is merely stressed over the first 50 cm of its length by metal blanks and therefore becomes worn only in this region. As soon as this region has worn down too far, the roll has to be replaced, although three quarters of the roll surface is still in good condition and is usable. For this reason alone, replacement cannot be avoided, since the first 50 cm of the roll no longer performs a grinding action when a large workpiece is introduced. The uneven wear of the roll and the resulting different pressure on the workpiece produce a grinding result of inferior quality.
In addition, a disadvantage with the known deburring and grinding machines is that the workpiece has to be inserted twice so that both main surfaces of the workpiece can be machined. A further disadvantage of the known machines is the high drive power, the large amount of space required and the high procurement and maintenance costs.
Furthermore, as shown in FIG. 1, revolving grinding belts which revolve against the feed direction of the workpiece to be ground are known from the general prior art. The grinding belts in this case have correspondingly large widths so that correspondingly wide workpieces can also be machined. In a similar manner to the known roll and brush tools, there is the disadvantage that the grinding belt becomes worn unevenly if the fed metal piece has a width which is less than the width of the grinding belt. As can be seen from FIG. 1, the grinding belt is oriented essentially vertically, the workpiece to be machined being pushed through below a narrow end face of the grinding belt. The grinding belt is driven by a drive shaft.
In addition to the fact that the wear of the grinding belts is uneven for the reasons already mentioned with regard to the aforesaid grinding machines, a further disadvantage consists in the fact that the grinding of plate- or strip-shaped workpieces having uneven surfaces varies sharply. It may be the case that only the arches are ground, whereas the grinding belt cannot penetrate into the recesses, as a result of which deposits, contaminants or the like cannot be removed from these regions. This leads to quality problems during the further processing or finishing of the surface.
An apparatus and a method for machining a strip- or plate-shaped metallic workpiece is known from publication WO 2004/039536 A1 of the generic type. This apparatus is especially suitable both for the deburring and edge radiusing of metallic workpieces and for the removal of oxide layers of cut surfaces and/or cut edges of the workpiece. Provided here in a revolutionary new way is a revolving conveying device provided with at least one brush, the conveying device directing the at least one brush at least approximately linearly past the region of the workpiece to be machined obliquely or transversely to the feed direction of the workpiece. The metallic workpiece is therefore for the first time no longer machined against or in the feed direction of the workpiece but rather obliquely or transversely thereto.
Due to the machining of the workpiece obliquely or transversely to the feed direction of the workpiece, uniform wear of the brush is achieved. This is the case irrespective of the dimensions of the workpiece to be machined. In contrast to the prior art, it is no longer necessary for the brush to be at least as wide as the workpiece to be machined. In addition, an advantage in the case of the publication of the generic type is that the brush, owing to the fact that it travels along the workpiece obliquely or transversely to the feed direction of the workpiece, can penetrate into every recess and can thus remove the oxide layer at all cut surfaces and edges. In addition, this leads to the edges being deburred or radiused.